Apparatus for electrostatic separation of material particles



BQ HOSFIELD 2,456,279

0R ELECTROSTATIC SEPARATION APPARATUS F OF MATERIAL PARTICLES Filed 0013. 24, 1945 l5- aan Q 1,3%,

BAsu. HoRsFl ELD INVENToR,

BY ma M A11-panas Patented Dec. 14, 1948 APPARATUS FOR ELECTROSTATIC SEPAR a TION 0F MATERIAL PARTICLES Basil Horsiield, Florence, Ala., assignor to Orefraction Incorporated, Pittsburgh, Pa., a corporation of Pennsylvania Application October 2.4, 1945, Serial No. 624,164

My invention relates to electrostatic separation of material particles, and the principal object of my invention is to provide new and improved apparatus for electrostatically separating material particles. This application is a division of my copending application Serial Number 279,129, led June 14, 1939, now abandoned.

In the drawing accompanying this specification, and forming a part of this application, I have shown for purposes of illustration, several forms which my invention may assume, and in this drawing:

Figure 1 is a fragmentary side elevation of apparatus embodying the invention,

Figure 2 is a fragmentary cross-sectional view taken on the line 2-2 of Figure 1, and

Figure 3 is a fragmentary cross-sectional view oi a detail of another embodiment.

Referringto Figures 1 and 2, the apparatus comprises a vertical, generally oblong rectangular wall 2|, carried in any suitable way by support means 20c. Thewall 2| hasv extending laterally therefrom a plurality of vertically spaced longitudinal ribs with upturned free margins, providing a plurality of gutters |43. The gutters M3 are parallel and extend from a particle feed box |390 to a particle discharge box 920.

The particle feed box |39c extends transversely of the gutters |43 and has a wall M90 which bears against the free margins of the gutters |43. The wall Itllc is provided with a slot |t|c of desired, suitable width. Particles to be separated are introduced into the open upper end of the feed box |39c. The slot Mic is of such length that particles are fed to al1 of the gutters M3 through the slot. Except for its open upper end and the slot Hilo, the particle feed box |390 is closed. A wall |t2c, abutting the right hand side of the feed box |390 and the right hand ends of the gutters |43, as viewed in Figure 1, closes these ends' of the gutters.

8 Claims. (Cl. 209.-131) f The particle discharge box 92C extends transversely of the gutters |63 at the discharge end thereof. that is, at the left hand end thereof as viewed in Figure l. The particle discharge box 920 is closed everywhere except on the side adjacent the discharge ends of the gutters |83, and except for a desired number of spouts |930. The spouts |93c are located just above respective dividing walls |960 forming chutes which, extend upwardly across the discharge box 92e to and flush with the bottom of a respective gutter |43. The construction and arrangement hence is such that particles discharged from the left hand end of a gutter |43 will slide down the respective dividing wall |96c of the discharge box 92e and out of the respective spout |936. The bottom wall of the dischargebox 92o may be inclined so as to. serve as a chute to the lowermos't spout |93c. Any desired number of dividing walls |960 and spouts |930n may be used, it being understood that if a dividing wall |96c is removed, the corresponding spout |930 will be plugged.

Electrode means 22e is provided for causing electrostatic action on the particles in the gutters |43. The electrode means 22e is here shown ,as of plate-type, substantially coextensive with the area of the wall 2|, and, accordingly, particles in the gutters |43 will come under the inuence of the electrode means 22e as they move in the gutters from the feed box 92e. The electrode means 2te is so positioned that it defines a selected vertical plane spaced from the free margins of the glitters |43. The electrode means 22o is, of ccurse, insulated from the remainder of the apparatus, and it may be adjustably supported in any suitable way.

In order to cause the particles to move in the gutters |43 from the feed end to the discharge end,the right hand end of the gutters |43, as viewed in `Figure 1, may be higher than the left hand end, so that the particles will slide from the feed end to the discharge end, or the gutters may be horizontal, and the support means 20c may be reciprocated, in a direction longitudinallly of the gutters M3, in such manner that the particles will progress in the gutters from the feed end to the discharge end, or any other suitable way of moving the particles in the gutters may be adopted, and 'if the particles are moved by reciprocating the support means 20c, the support means may be reciprocated in any suitable manner, for example, by mechanism such as is shown in my prior application 594.829, now Patent 2,392,044.

A particle receiving means 9| c is provided which, as here shown, is in the form of an upwardly open trough extending longitudinally below the lowermost gutter |43 and of sufficient transverse width to receive particles which, after having been lifted out of any one of the gutters,

fall through the free vertical space left between the electrodel means 22e and the free margins of the gutters. The trough 9|c is here shown as carried by the support means 20c. The trough 9 |c may also be provided with dividing walls |96c and spouts |930 and, if desired, the walls |96c may be removable and/or adjustable, and the spouts |930 may be selectively plugged or left lOpen.

tric charge therefrom, and are otherwise so constructed and arranged that particles of higher electrostatic susceptibility will be lifted out of the gutters when a sufficient difference of electric potential exists between the gutters and the electrode means 22e. It will be obvious that such dinerence of potential may be applied by conductors (not shown) connecting the gutters |43 (or |45), or the support 20c, to one of the terminals of a high potential source and the electrode means 22e to the other.

The operation of the apparatus is as follows. While particles are moving in the gutters |43 from the feed box |39c toward the discharge box 02e, the electrode means 22e andthe gutters |43 are subjected to a predetermined difference of electric potential.

be discharged from a spout further away fromthe feed box. Particles not so lifted out of the gutters |43, either because they are insufficiently susceptible or are non-susceptible, progress therein until they are discharged into the discharge A box 92e and from thence into and through the respective spouts I93c connected to the discharge box 92e.

For best results, the gutters |43 (or |45) should be vertically spaced suiliciently so that particles in the gutters will be electrostatically shielded as little as possible, in other words, the spacing should be suillcient so that particles in the gutters may be subjected to electrostatic action by the electrode means 22o. I have found that when the gutters are in a, common general plane which is substantially vertical, the gutters are sumciently vertically spaced if the space between adjacent gutters is approximately one and one half times the overall transverse width of a gutter.

From the foregoing it will be apparent to those skilled in the art that each of the illustrated embodiments of the invention provides a new and improved apparatus for separation of material particles, and accordingly, each accomplishes the principal object of the invention;y On the other hand, it also will be obvious to those skilled in the art that the illustrated embodiments of the invention may be variously changed and modied, or features thereof, singly or collectively,v

embodied in other combinations than those illustrated, without departing from the spirit of the -invention, or sacrificing all of the advantages thereof, and that accordingly, the disclosure here# Particles of higher electrostatic susceptibility are lifted, by .electrostatic substantially vertical plane spaced horizontally from said gutter means; particle receiving means; said gutter means and said electrode means and said particle-receiving means being relatively so rpositioned that the space left between said electrode means and said gutter means extends freely downwardly into said particle receiving means; and said electrode means and said gutter means being so constructed and arranged that when they are subjected to a suificientdifference of electric potential, particles of higher susceptibility will be lifted, by electrostatic action, out of said gutter means into said vertical space and fall downwardly therein into said particle receiving means.

2. Apparatus for separation of material particles, comprising: means, for supporting the particles, constructed and arranged to cause the particles to progress in one direction, said supporting means comprising a plurality of gutters, for the particles, spaced so as to be at different levels; functionally plate-type electrode means positioned to define a substantially vertical plane spaced horizontally from said gutters; particle receiving means; said gutters and said electrode means and said particle receiving means being relatively so positioned that the space left between said electrode means and said gutters extends freely downwardly into said particle receiving means; and said electrode means and said gutters being so constructed and arranged that when they are subjected to a sufficient difference of electric potential, particles of higher susceptibility will be lifted, by electrostatic action, out of said gutters into said vertical space and fall downwardly therein into said particle receiving means.

3. Apparatus for separation of material particles, comprising: means, for supporting the particles, constructed and arranged to cause the particles to progress in one direction, said supporting means comprising a plurality of gutters, for the particles, spaced so as to be at dierent levels; particle feed means constructed and arranged to feed particles to all of said gutters; functionally plate -type electrode means positioned to dene a substantially vertical plane spaced horizontally from said gutters; particle receiving means; said gutters and said electrode means and said particle receiving means being relatively so positioned'that the space left between said electrode means andsaid gutters extends freely downwardly into said particle receiving means; and said electrode means and said gutters being so constructed and arranged that when they are subjected to a suiiicient difference of electric potential, particles of higher susceptibility will be lifted, by electrostatic action, out of said gutters into said vertical space and fall downwardly therein into said particle receiving means.

4. Apparatus for separation of material particles, comprising: means for supporting the particles, comprising a plurality of spaced gutters dis. posed at different levels, and constructed and arranged to cause the particles to progress longitudinally of said gutters; functionally plate-type electrode means positioned to dene a substantially vertical plane spaced horizontally from said gutters; the space between adjacent gutters being sumcient so that particles in said gutters may be subjected to electrostatic action by said electrode means; and said electrode means and said gutters being so constructed and arranged that when they are subjected to a sumcient difference of electric potential, particles of higher sixscepti bility will be lifted, by electrostatic action, out of said gutters into the space between said electrode means positioned to define a substantially verti-` cal plane spaced horizontally from said gutters; the space between adjacent gutters being suiicient so that particles in said gutters may be sub- -jected to electrostatic action by said electrode means; and said electrode means and said gutters being so constructed and arranged that when they are subjected to a sufficient difference of electric potential, particles of higher susceptibility will be lifted, by electrostatic action, out of said gutters into the space between said electrode means and said gutters.

6. Apparatus for separation of material particles, comprising: means, for supporting the particles, constructed and arranged to cause the particles to progress in one direction, said supporting means comprising a plurality of gutters, for the particles, disposed in a common substantially vertical plane and spaced so as to be at'different levels; electrode means disposed laterally spaced from said gutters; the space between .adjacent gutters being approximately at least one and one half times the width of said gutters; and said electrode means and said gutters being so constructed and arranged that when they are subparticles, disposed in a common substantially vertical plane and spaced so as to be at differentV levels; functionally plate-type electrode means positioned to define a substantially vertical plane spaced horizontally from said gutters; the space between adjacent gutters being approximately at least one and one half times the width of said gutters; and said electrode means and said gutters being so constructed and arranged that when they are subjected to a suiiicient difference of electric potential, particles of higher susceptibility will be lifted, by electrostatic action, out ofsaid gutters into the space between said electrode means and said gutters.

8. Apparatus for separation of material particles, comprising: means, for supporting the particles, constructed and arranged to cause the particles to progress in one direction, said supporting means comprising a plurality of gutters, for the particles, disposed in a common substantially vertical plane and spaced so as to be at diiferent levels; particle feed means constructed andarranged to feed particles to all of said gutters; functionally plate-type electrode means positioned to deiine a substantially vertical plane spaced horizontally from said gutters; the space between adjacent gutters being approximately at least one and one half times the width of said gutters; and said electrode means and said gutters being so constructed and arranged that when they are subjected to a sulcient difference of electric potential, particles of higher susceptibility will be lifted, by electrostaticaction, out of said gutters into the space between said electrode means and said gutters.

BASIL HORSFIELD.

vREFERENCES CITED The following references are of record in the 40 i'lle of this patent:

UNITED STATES PATENTS Name Date Winnie Dec. 30. 1913 Horsfleld Jan. 1, 1946 Number 

